I think that all modern glasses/sun glasses have UV blocking these days, don't they?
I got a bell vortex helmet and a Transitions shield and love it. It doesn't get as dark as I'd really like but I haven't had to hold my hand up to block the sun
Yeah, I saw that Bell transitioning shield online when I was looking for a helmet. It is a good idea, although it looks like it might jack the price of the shield up a LOT. I tend to have to replace shields every year, even without a whole lot of miles, so I imagine for some people that could get expensive.
To me, the cost is worth it, even if I have to replace it annually. FWIW, it was about $120. Actually more than the helmet.